Cortical Tonotopic Map Changes in Humans Are Larger in Hearing Loss Than in Additional Tinnitus.

Summary

Measured cortical responses to loudness-matched tones in participants with high-frequency hearing loss, with and without tinnitus, plus controls. Both hearing-loss groups showed elevated high-frequency sound-evoked cortical activation versus controls, but adding tinnitus on top of hearing loss did not add much further map change, suggesting tonotopic reorganization tracks the hearing loss itself more closely than it tracks tinnitus specifically.

Key findings

• Cortical map changes were present in both hearing-loss groups (with and without tinnitus) versus controls.
• Map changes were similar in size between the hearing-loss-only and hearing-loss-plus-tinnitus groups.
• Suggests map reorganization may be a marker of hearing-loss extent rather than a direct cause of tinnitus.